Weighing-machine.



J'HN BISHOP ND EDWARD P. HUGHES, OF DETROIT, MICHIGAN,

WEIGHNG-MACEINE Specification of Letters Patent.

Application led February 9, 1914. Serial No. 817,532.

To all whom it may concern .f

Be itknown that we, JonN Bisnor and EDWARD P. HUGi-ins, `citizens of Great Britain and the United States, respectively, residing at Detroit, county of Wayne, yand State of Michigan, have` invented certain new and useful Improvements in Weighing- Machines, of which the following is a specification. Y .i

`This invention relates to' weighing machines, and more especially to that variety thereof which are vknown las platform scales, and it has for one of its objects the provision of an improved mechanism which comprises almember operated by the platform so as to have \a predeterminediweight exert an increased counterbalance effect or resistance proportionate to the downward movement of said latform, said increased leverage'being imparted to saidA member in an entirely automatic manner, that is to say: without anyaid4 of. the o erator in either shifting the weight or ad ing thereto.

The invention has, furthermore, for itsv object the provision of means whereby the counter-balance weight will be retarded in its movement to the desired degree during the descent of the platform, so that the latter will descend evenly until the counterpoise has been attained and without any viration at that time.

Further objects ofthe invention will here` inafter appear and be more particularly deable platform llwhich is adapted to receive i the article to be'weighed, this platform being supported in any desired or well-known manner on the main beam 12 which is fulcrumed at 13A and is connected at its rear,

end, as at 14, to an upwardly extending rod 15. This rod has at its upper end a flexible band 16 which is wound around a drum 17 of substantially uniform diameter, so that the latter will be rotated bythe descent of v the platform 11, l

' The counterweight, whereby resistance is offered to the rotation of this drum, is in the Patented Mar. 9, 1915.

present instance carried by a member so formed as to increase this resistance by virtue of the weight 1veeoming effective at gra-duallv increasing distances from the center of said drum. This member comprises a 1ever shaped in the form ofa parabola and designated as a snail S the outer surface of which is formed so as to have the successive points thereof gradually increasing in dis-K tance from the center of the drum 17, and' the cord 18 is attached to said snail near the center thereof, as at 19, Attached to the lower end of the cord 18 is a weight Wand the cord 18 is, by the descent of the platform 11, wound upon the snaihand in this manner thc distanceof the pulling point of the cord on the snail will therefore be gradually increased as theband 16 is pulled down` wardly. This means that this ,increasing distance will naturally ezffefrtny proportionate increase in resistance, without sadding any further load'io the weight W.

In order to bring the parts rimarily to balance, a shiftable counterwcig t such as w may be employed upon a lever or rod 20 attached to the drum 17 as clearly shown. In the present instance the mechanism is so organized that the downward movement of the platform to its limit, will rotate the' drum and .snail for a little more than onehalf rotation, and a pointer or hand 21 attached to the spindle of the drum may cooperate with a dial 22 to indicate the load on the platform 11. l

As above stated, means are provided for retarding the movement of the weight W so as to obviate the vibration or back-and-forth movement of the indicator hand when the mechanism has arrived near its point of balance, and we accomplish this object by providing a tube 23 which is closed at the bottom and filled with oil, and in which the weight may freely slide so as to allow said weight to rise without establishing a vacant space in the lower end of said tube, or in other words: to allow the oil above the weight to pass below the same durin the ascent of the weight YV, i A by-pass tu e 24C havin a regulating valve 25 may be .em` ploye for increasing or decreasing the freedom of flow of oil from the upper po t tion of the tube into the lower end thereo or vice versa. In order to maintain free vertical movement of the weight W within l the tube, while the upper end of the pord 18 will be deflected in accordance to the position of the snail, We provide a guide pulley tion, and it is to be understood that this v whereby when said snail is rotated ratio of increase :may be varied as desired, without departing from the spirit of the invention.' Likewise it should be understood that such increase in linear pitch may be changed, and that other portionsfof the mechanism may be altered to suit the /required conditions, 'Without leaving the/gist of the invention out of consideration. g

`We claim :wf/ '5 f 1. A weighing machine comprising a loadreceiving platform, a rotatable drum coperatively connected. therewith, a snail carried by said drum, a weight, and a flexible band for connecting said weight and snail,

the active point of connection between said weight and snail will be proportionately moved away from the center during the descent of said platform under load, a vertical'liquid containing tube containing said weight to retard the movement thereof, and a guide for said band attached to said tube for guiding the Weight thereon. I

2. A weighing machine comprising a loadreceiving platform, a weight counterbalancing the same, means for automatically varying the resistance offered by said wei ht proportionately to the descent of said p atform under load, a liquid-containing tube closed at the bottom loosely surrounding and for guiding said weight, and for retarding the upwardmovement of said counter-balancing weight. f

3. A wei hing machine comprising a loadreceiving p atform, a weight counter-balancing the same, means for automatically varying the resistance of said weight proportionately to the descent of said platform under load, a liquid containing tube containing said weight and a by-pass connecting the upper end and lower end of said tube and having a regulating valve for retarding the upward movement of said counter-balancing weight.

In testimony whereof We aix our signatures in presence of two witnesses.

' JOHN BISHOP.

EDWARD P. HUGHES. Witnessesz' H. D'.'MACD0NALD, Cms. F. ScHamLz. 

